Try CRYSTAL

What you can do with the demo version

A CRYSTAL23 evaluation copy is available free of charge for Linux and Windows operating systems. All functionalities of the full version are active, the only limit is the number of atoms, restricted to 10 per primitive cell.
For a quick introduction to CRYSTAL input and output a guided "CRYSTAL tour" is suggested.

Here below some example of systems that can be studied with the evaluation version of CRYSTAL23.

How to get the demo version

To get an evaluation copy you first have to register, you'll find the download link in your personal account page.